It is generally recognized that the development of dental plaque begins with the adhesion of bacteria to the teeth. Bacterial adhesion to tooth surfaces usually involves stereospecific interactions between cell surface binding proteins, referred to as adhesins, and cognate structures which form binding sites either in salivary pellicle, on the surfaces of other bacteria resident in plaque, or in the extracellular plaque matrix (Gibbons, R. J.; J Dent Res 68:750-760). Plaque generally consists of bacteria, bacterial end products such as polysaccharides, inorganic salts and salivary proteins. Dextrans with their predominant alpha-1,6-glycosidic linkages as appeared in the glucan structures found in a plaque matrix are known to mediate binding of oral bacteria in the oral environment. Plaque bacteria ferment dietary carbohydrates to organic acids which demineralize enamel resulting in tooth decay. Streptococcus mutans and Actinomyces viscosus are pathological bacterial species present in dental plaque and which were found to possess a high cariogenic potential. There is a continuing need for effective and commercially feasible antiplaque agents. Streptococcus Sanguis is a primary colonizer of teeth surface which allows attachment of pathological bacteria.
Polyethylene glycol grafted surfaces are known to repel proteins. Duval et al., "Synthesis and Characterization of Some Covalent Dextran-Polyethylene Glycol Derivatives", Carbohydrate Polymers 15, 233 (1991) discloses randomly substituted copolymers of polyethylene glycol and polysaccharides. Japanese Patent Application 49010937 discloses use of glycol-modified polysaccharides or salts thereof in cosmetic lotions and creams. Like Duval et al., the Japanese reference employs randomly substituted copolymers. The copolymers taught by the present invention differ from the copolymers disclosed by Duval et al. and by the Japanese reference in at least that the present copolymers are block copolymers where at least one polysaccharide block is substituted with at least one polyalkylene oxide at the anomeric carbon of the polysaccharide.
Accordingly, it is an object of the present invention to provide novel diblock copolymers of polysaccharides and polyalkylene oxides.
It is another object of the present invention to provide oral hygiene non-food compositions containing the diblock copolymers as antiplaque or anticalculus agents.
A further object of the present invention is to provide antiplaque/anticalculus agents having significant activity and being derived from safe starting materials such as polysaccharides and polyalkylene oxides.
It is yet another object of the present invention to provide a method of eliminating or substantially reducing bacterial aggregation in an oral cavity or in an aqueous medium.
It is still another object of the invention to provide a method of preventing or substantially reducing bacterial aggregation or coaggregation in fermentation systems.
It is yet another object of the present invention to provide unique block copolymer that will function as effective dispersing agents for bacterial dispersions that would otherwise aggregate during storage.
These and other objects of the present invention will become more apparent in light of the detailed description and examples which follow.